QLC stands for 'Query List Comprehension' which is used with Mnesia database, to enhance the operational ability of Mnesia. QLC having our own documentation as a part of the OTP documentation set.Main features of QLC with Mnesia are as follows:

QLC is used to optimize the query compiler for Mnesia Database. and for making Mnesia DBMS more efficient.QLC is used like a database programming language for Mnesia and it includes a notation called "list comprehensions" and can be used to make complex database queries over a set of tables.